16 X 2 display gone fritzy

I was prototyping something and life was good. The Amerlight TM LCD Module 2X16 was showing what it was supposed to show. Then all of a sudden the right half of the display started showing garbage. Then the whole thing went downhill. Backlight still works, areas for the letters still light up, but all I see is blocks. Checked wiring, all looks good. Tried resetting the Nano and re-uploading the sketch. All indications are that the Nano is fine and things are running, but still no joy on the display.

What's the best way to test the display as a standalone to see if the problem is there or if it's something to do with my Nano's output? Anybody see this sort of thing before?

The Amerlight TM LCD Module 2X16 was showing what it was supposed to show. Then all of a sudden the right half of the display started showing garbage.

So two possibilities:-

  1. You wired it up wrong and fried the part
  2. Your wiring has come disconnected
    Either way you need to post a schematic and a photo of what you have got.

When you have half a display with garbage, an internal bad connection is another possibility.
The module consists of 2 parts: the PCB and the glass.
They are connected by a rubber like strip and the bezel around the glass is supposed to press these parts together.
Sometimes that bezel doesn't seem to do it's job that well anymore.
Take a look at the bottom of the PCB, you will see some parts of the bezel coming through.
Try to bend them a bit so the bezel will be tightened to the glass and the PCB.
Do not try to remove the bezel and clean the contacts, that will for sure end up in a destroyed display.

Good tip on the bezel seating. Thanks. I was hoping there might be some known oddities with those LCD panels.

Sadly, it looks like a classic Eye-Dee-Ten-Tee error on my part rather than a hardware quality issue. The Nano's D8 looks like it was accidentally connected to the 5V. Maybe the most amazing part is that it worked as long as it did! (some 15+ minutes) It also probably explains why the other peripheral I was trying to drive wasn't getting any output. The D8 was supposed to be driving the clock on that other part, but it wasn't hooked up. Classic fatfinger mistake on a protoboard. Mea culpa.

I checked the LCD display using an another Arduino I forgot I had here and it checked out OK, so it's almost certainly the Nano. I'll try some simple "light up the LED" tests on the thing and see if I've just lost D8 or if it cascaded through and fried the lot.